Currently, underfill material may be deposited between a die and substrate to promote adhesion between the die and substrate and/or to protect features of the die and substrate such as interconnect structures from environmental hazards. A coefficient of thermal expansion (CTE) of the underfill material may be designed to match, to the extent possible, a CTE of the die and/or substrate in order to reduce defects such as cracks, delamination, or other defects associated with thermal expansion or contraction of the die and/or substrate. Techniques are being investigated to reduce CTE of underfill material for some scenarios. For example, one technique includes adding inorganic fillers to reduce CTE of underfill materials. However, addition of inorganic fillers may also increase a viscosity of the underfill material, which may adversely affect processing of the underfill material. A higher viscosity may render the underfill material unsuitable for deposition in some cases.